2 Answers
2

According to the Minecraft Wiki page on squid and fishing, squid will spawn at any depth water, any light level, and the fishing requirements are:

at minimum, the body of water should be 1 block by about 10 for casting distance. The water can be 1×1, but this requires the player to cast upwards so that the bobber will land in the water. This ensures the bobber's initial velocity is wasted moving up, so that it does not hit any blocks falling back down.

Squids are only able to spawn at levels above y=4o. If the house is built in classic flat mode, then it will be hard, but not impossible, to spawn a squid. You would need to get a small body of water above y=40.

If it is in a normal world on ground surface, then there should probably be no problem as long as the lake is large enough to fit fish/squids. One block in theory should be deep enough as long as it is wide and long enough to spawn squids.

I am sadly unsure currently what is the levels that fish can spawn at though.